The $8500 quote was for 25 PCBs with ~250 components plus 50 PCBs with 1 IC and ~30 caps. Personally, I think that's rather expensive

That sounds expensive to me unless maybe it includes x-raying of BGAs etc. - ask some other, smaller assembly houses.

The was the cheapest of 10 places I tried. That was http://www.aapcb.com, and they seemed cheaper than anyone else. In fact, someone suggested them to me.

This is the problem with "normal companies" and "normal business models"... they have substantial daily expenses (called "salaries"), and they need to pay those expenses even when "times are lean". Plus, their typical customers are mostly "real companies" with substantial cash-flow. What lone-ranger developers and hobbyists and startups need is something much more informal, efficient and cost effective.

'Informal' reminds me - most places are ISO9001 or whatever and seem to spend a lot of time going through their administrative procedures, which must add cost. My normal PCB assembler insists on doing ridiculous levels of packaging - individually bagged & bubble-wrapped PCBs are a PITA to unwrap wthen there's a hundred of them.

Another classic recent example : a contractor was making some cable looms for us. The wire they were going to use was due in the day after I visted them, so I asked them to stick a metre or so of each colour in the post so I could check overall bundle size, bundled bend radius etc. 2 days later I got an envelope containing ten individually bagged & labelled lengths of _exaxctly 1m_ of each and a delivery note.

The solo IC in the center of the top side of the small PCB is a 48-pad iLCC "image sensor". The iLCC package is pretty much the same as a QFN, except of course the top surface of the package is a glass window to let the image fall upon the image sensor. The other ICs on the small PCB (on the other side) will not usually be stuffed (though all the caps near the center of the PCB will be stuffed to bypass the 3 voltages the image sensor requires).

For me, "pick-and-place" isn't just for fun, it's for:----- placing 0201 caps (see bottom side of BGA components on the larger PCB)----- placing all BGAs precisely----- placing all QFNs precisely

I can handle 0402s manually just fine. And maybe with a stereo microscope, vacuum pick-up pencil, and enough practice, I can handle the 0201s too. But so far at least, I cannot make myself believe that I can precisely place BGAs and QFNs by hand... EVERY TIME (which is what I need).

PS: I'm posting this message in the other two active PaP threads too, just in case.

I think the QFNs and BGAs would be doable by hand, but you'd probably want to have some alignment marks on the copper layer. Remember they will self-align on the pads as long as the paste print is good and they are within maybe 20% of the pad pitch.Some sort of precise adjusting jig would certainly help - e.g. PCB on a simple XY table and a vacuum pen that can be wound up/down. I doubt it would cost much to make something to do this, even if you used micrometer screws for the adjustments.

You may also investigate getting a subcontractor to just do the BGAs with good manual equipment.

No you were clear, but advanced circuits does offer kitting services. I got a quote from them for a small board, it wasn't that bad.

Seeedstudio also does reasonably cheap kitting from what i understand but i only have experience of their end products.

I called them and they forwarded me to someone at http://www.onestopassembly.com, so I guess they are one of the near-infinite places who are actually fronting for someone else. That is, unless one of them is a "division" of the other. My first guess is, they will be somewhat cheaper than http://www.aapcb.com.

Interesting, I wonder if thats a recent change, I did a quote with them a couple of months ago, and resused the email addresses they'd sent me, and i hadn't heard back yet.. I did call them and talk to people there about the quotes too..

which sucks because i'd figured out all the pricing and quotes with them already.

charliex wrote:Interesting, I wonder if thats a recent change, I did a quote with them a couple of months ago, and resused the email addresses they'd sent me, and i hadn't heard back yet.. I did call them and talk to people there about the quotes too..

which sucks because i'd figured out all the pricing and quotes with them already.

Another "general" note about having prototype PCB assembly done: Every time I got a custom quote from a PCB assembly company (giving them my exact BOM), the custom quote was very substantially higher than the automatic online quote, even though I submitted all requested information accurately in both cases. I'm guessing these places won't try to raise a price offered by their online quoting system after a PCB assembly job is submitted, so I suggest folks NOT ask for custom quotes (or get a quote in some other name, so you can then choose which quote to accept).

Sounds like good advice, i'm just about ready to do another run of 50 small PCB's, not much, but i'm having issues sourcing some components still. I'm glad that the leadless VDFN's are layout compatible with the SOIC8Ws though, that saves me some hassle, since i can switch between em.

I was going to go with advanced circuits, but i just don't know at the moment, especially if they are outsourcing, i might give silver circuits a bash, i've heard a couple of decent reviews.

What do you figure your cost per PCB is by outsource-assembly-outfits? From my initial quotes from places like onestopassembly and quick calculations I determined buying my own soldering system (stencil-printer, pick-and-place machine, multi-zone conveyor reflow oven) was cheaper. In fact, it appeared to me that I could pay for all the equipment and accessories in 1 to 2 years.

My 12sq in, board with 69 placements of 32 unique smt parts in a run of q 100 from http://www.screamingcircuits.com is quoted at about $15/board ( http://goo.gl/WAuU ); If I had my own production line I probably couldn't produce the boards for anything less than $2.00/board. This assumes one experienced $17/hr tech is operating the line, plus any direct overhead (7.5% ss tax, computer, desk, banned, slak, etc); So really owning my own line will save me $13/unit, or maybe 13% off my costs. Granted, this is big, but I still cannot justify the risk of ponying up $50+k in equipment, space, overhead, until that line can be kept pretty busy; For me, that is about 10k units/yrwhich translates to roughly $1m gross of business per year.

bcoggs wrote:My 12sq in, board with 69 placements of 32 unique smt parts in a run of q 100 from http://www.screamingcircuits.com is quoted at about $15/board ( http://goo.gl/WAuU ); If I had my own production line I probably couldn't produce the boards for anything less than $2.00/board. This assumes one experienced $17/hr tech is operating the line, plus any direct overhead (7.5% ss tax, computer, desk, banned, slak, etc); So really owning my own line will save me $13/unit, or maybe 13% off my costs. Granted, this is big, but I still cannot justify the risk of ponying up $50+k in equipment, space, overhead, until that line can be kept pretty busy; For me, that is about 10k units/yrwhich translates to roughly $1m gross of business per year. YMMV..c

Your calculations seems about right to me, though I'm not sure I'd pay a $17/hour techie to operate the line until volume got significant. But I can say this because I would only be running 2 different PCBs for probably the first year or so. I figure (or rather, "hope") the attention needed to keep a pick-and-place machine running would be minimal in our case, because we never need to exchange component reels and rarely need to change programs (only 2 PCBs). Since our second PCB only has 2 components that aren't on the first PCB, we can have all component reels always loaded. I also assume (hope) that we could hear an audible indication that "the machine needs attention", like when a reel runs empty.

My back-of-the-envelope calculation assumes we need to spend $50K on stencil-printer, pick-and-place, multi-zone [conveyor] reflow oven. Therefore, once we run 10,000 PCBs through the system, I figure the machine has paid for itself at roughly $5 per PCB. This does not include electricity, so make that $8 per PCB, plus or minus a couple bucks.

If and when "the business changes" and we need to switch between several PCBs and a wide variety of components, an operator would be necessary.

One other idea I had, especially for the "early days", is to apply solderpaste with the pick and place machine rather than a stencil printer. This would eliminate the need for human hours to carefully apply and inspect the solderpaste with a stencil-printer. The speed the pick-and-place machines apply solderpaste dots is much faster than grabbing components... generally about 5 to 10 times faster (since the head need only move about 1mm between solderpaste dots compared to several feet to grab and place components). I would imagine the number of defects due to bad solderpaste application and alignment would be greatly reduced with a dispenser system. Can anyone who has tried both ways to apply solderpaste either confirm or deny this theory (and provide general comments and advice)? I'd appreciate that.